This invention relates to testing apparatus and methods in general and, in particular to a new and useful apparatus and method for testing for nickel aerosols in a gas, such as air.
The only allowable low limit value of nickel dust in a workplace is 0.05 mg/m.sup.3, according to MAK-Value-list 1979, which shows this dust to be a potential danger. Frequent and regular supervision of nickel aerosols in the air is therefore necessary to avoid health hazards.
A known method for determining nickel aerosols, employs a cellulose membrane filter for taking samples through which the gas to be tested is sucked with a pump. Then, in a first step, the organic filter material is dissolved in concentrated, warm nitric acid and the liquid is nearly completely evaporated. A mixture of concentrated nitric acid and perchloric acid is added to the remaining concentrate, and this mixture is then evaporated at a higher temperature (400.degree. C.). After cooling, the residue is dissolved in thinned nitric acid. The nickel determination is performed from this solution in the oxidizing flame of an atomic absorption spectrophotometer.
The large equipment requirements of this process and the skilled personnel which is required are some of the disadvantages of this process. The performance is cumbersome and time-consuming and the test results are not readily available at the place of the sample-taking (NIOSH Manual of Analytical Methods, Second Edition, Volume 3, page 206).
In a known test tube with three or more separately disposed reagents or reagent layers, respectively, are one or more reagents or reagent layers, preplaced relative to an indicator layer, and positioned in one or more breakable ampoules. The testing tube itself is also breakable in the region of the ampoule and is provided there with a tubing cover. After breaking of the test tube, it seals the interior of the tube against the outside (See German Pat. No. 1,093,114).